ANNALS 



OP 



PHILOSOPHY. 



DECEMBER, 1814. 



Article I. 



Experiments to determine the Definite Proportions in which the 

 Elements of Organic Nature are combined. l>y Jacob Berzelius, 

 M.D. F. R.S. "Professor of Chemistry at Stockholm. 



(Continued from p. 331.) 



XHE best experiments on organic substances are certainly tliose 

 which Gay-Lussac and Thenard have published in their Recherches 

 Physico-Chimiques, ii. 2G5. These chemists burnt various ternary 

 and quaternary oxides with hyper-oxymuriate of potash, moistened 

 with water, and made up with it into small balls. These balls were 

 dried at the temperature of boiling water, and were afterwards 

 burnt in an apparatus contrived on purpose. They collected over 

 mercury the gaseous products of the combustion, and determined 

 exactly the relative volumes of carbonic acid gas and oxygen gas. 

 The quantity of oxygen furnished by the hyper-oxymuriate being 

 known, and added to the weight of the substance decomposed, they 

 found what the products of the combustion ought to weigh. By 

 finding the weight of the carbonic acid and oxygen evolved, and 

 subtracting it from the original weight, they obtained the quantity 

 of water formed. The quantity of carbonic acid and water thus 

 found indicated the quantities of carbon and hydrogen in the sub- 

 stance analysed, while the superfluous portion of oxygen above that 

 yielded by the salt was obviously likewise a constituent of the sub- 

 stance. We '-hall find afterwards that several of the analyses of 

 these chemists agree with my own. 



] trust 1 shrill be permitted here to make a few observations upon 

 tin- Work of these chemists, so justly celebrated, in order to explain 

 my reasons for not following; their analytical method, and of only 



Vol. IV. N°Vl 2C 



